1. Field of the Invention
The present invention generally relates to an optical imaging lens set and an electronic device which includes such optical imaging lens set. Specifically speaking, the present invention is directed to a shorter optical imaging lens set of four lens elements and a shorter electronic device which includes such optical imaging lens set of four lens elements.
2. Description of the Prior Art
In recent years, the popularity of mobile phones and digital cameras makes the sizes of various portable electronic products reduce quickly, and so does that of the photography modules. The current trend of research is to develop an optical imaging lens set of a shorter length with uncompromised good quality. The most important characters of an optical imaging lens set are image quality and size.
The designing of the optical lens is not only just scaling down the optical lens which has good optical performance, but also needs to consider the material characteristics and satisfying some requirements like assembly yield.
For example, U.S. Pat. No. 7,848,032, U.S. Pat. No. 8,284,502, and U.S. Pat. No. 8,179,616 all disclose an optical imaging lens set of four lens elements with a total length of 8 mm or larger. In particular, U.S. Pat. No. 8,179,616 even has a total length of 11 mm, which is not ideal for the size reduction of the portable devices.
Therefore, how to reduce the total length of a photographic device, but still maintain good optical performance, is an important objective to research.